mirror of
https://github.com/hermitcore/libhermit.git
synced 2025-03-09 00:00:03 +01:00
92 lines
2.7 KiB
Go
92 lines
2.7 KiB
Go
/*
|
|
* Copyright (c) 2016, Stefan Lankes, RWTH Aachen University
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* * Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this
|
|
* software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
|
|
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
|
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"strconv"
|
|
"time"
|
|
"runtime"
|
|
)
|
|
|
|
var step float64
|
|
|
|
func term(ch chan float64, start, end int) {
|
|
var res float64
|
|
|
|
for i := start; i < end; i++ {
|
|
x := (float64(i) + 0.5) * step
|
|
res += 4.0 / (1.0 + x * x)
|
|
}
|
|
|
|
ch <- res
|
|
}
|
|
|
|
func main() {
|
|
var num_steps int
|
|
ch := make(chan float64)
|
|
max_coroutines := runtime.NumCPU()
|
|
|
|
if len(os.Args) > 1 {
|
|
num_steps, _ = strconv.Atoi(os.Args[1])
|
|
}
|
|
if num_steps < 100 {
|
|
num_steps = 1000000
|
|
}
|
|
fmt.Println("num_steps : ", num_steps)
|
|
|
|
sum := float64(0)
|
|
step = 1.0 / float64(num_steps)
|
|
|
|
start := time.Now()
|
|
|
|
for i := 0; i < max_coroutines; i++ {
|
|
start := (num_steps / max_coroutines) * i
|
|
end := (num_steps / max_coroutines) * (i+1)
|
|
|
|
go term(ch, start, end)
|
|
}
|
|
|
|
for i := 0; i < max_coroutines; i++ {
|
|
sum += <-ch
|
|
}
|
|
|
|
elapsed := time.Since(start)
|
|
|
|
fmt.Println("Pi : ", sum*step)
|
|
fmt.Println("Time : ", elapsed)
|
|
|
|
s := new(runtime.MemStats)
|
|
runtime.ReadMemStats(s)
|
|
|
|
fmt.Println("Alloc : ", s.Alloc)
|
|
fmt.Println("Total Alloc : ", s.TotalAlloc)
|
|
fmt.Println("Sys : ", s.Sys)
|
|
fmt.Println("Lookups : ", s.Lookups)
|
|
}
|